How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat manufacturers, and we proudly install them on a frequent basis in West Chester. They’re durable and reliable. Plus, Honeywell is frequently improving its technology, bringing more features for your household.

Nevertheless, each thermostat can experience errors occasionally. That’s why we’ve compiled this valuable guidebook to run through troubleshooting.

While you can often repair most thermostat problems by yourself, they occasionally call for Expert help. Our heating and cooling pros are here to help when you need us. We’re just a call away at 484-401-7577.

Let’s get started with the process by figuring out what model of thermostat your residence has.

What Kind of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t run into error codes with this one, but it’s also the least efficient for lowering utility costs.
  • Programmable—This thermostat includes a digital screen and arrows you use to determine your desired temperature. You can also choose daily programs to reduce the temperature when you’re gone and set it higher when you come home.
  • Smart—You won’t have to schedule any programs on this thermostat, as it learns your schedule. It instinctively changes the temperature when you or loved ones are gone to help you save on energy bills. You can also raise or lower the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As you know the majority of technologically advanced solutions, there are common malfunctions that may take place. Many of these problems don’t call for professional assistance and are simple to repair by yourself.

Common Honeywell Thermostat Issues

All thermostats have a unique group of codes assigned to the troubles that take place.

Think how simple it can be to fix a computer by restarting it. In many instances, troubleshooting a thermostat can be just as easy.

Here is a guide to the most encountered Honeywell thermostat issues. These include the following programmable thermostats:

Display is Blank

If the display is clear on your programmable thermostat, you may need to install new batteries. If that doesn’t take care of the problem or you use a smart thermostat, there might be a wiring issue.

Next, you should make sure the power is enabled for your furnace or air handler. Make sure the switch near the indoor unit is switched “up”.

Additionally, you should confirm all furnace cabinet or air handler doors/panels are tightly in place.

A panel that isn’t tight may activate the safety switch, which disconnects power to the equipment.

Infrequently, an empty screen might indicate you will need to buy a new thermostat.

Heating and Cooling Equipment Won’t Turn On

Check that your thermostat is switched to “cool” or “heat,” not “off.”

When it’s hot, confirm you schedule the thermostat lower than the ambient temperature. When it’s cool, make sure it’s higher. This sounds absurd, but we’ve seen it happen a lot of times.

Make sure the power switch close to your indoor equipment is in the “on” position. You should also make sure the cabinet doors or panels are tight on your furnace cabinet or air handler. A loose panel can trigger the safety switch, cutting off power to the system.

System still won’t start? Confirm circuit breakers haven’t turned off and that your HVAC equipment isn’t displaying error codes.

“Cool On” or “Heat On” is Blinking

To begin, verify your thermostat is on “cool” or “heat.”

Then, ensure it’s signaling the right system to turn on. This is often demonstrated by “cool on,” “heat on” or an illustration.

If this set of words or the picture is pulsing, your thermostat is in a five-minute delay status. This setting protects your unit from harmful short cycling. This can happen if you lose electricity.

Honeywell Thermostat-Specific Error Codes

Honeywell Lyric™ T5 Wi-Fi (RCHT8612WF/RCHT9510WFW)

  • 164—Heat pump requires service. Call Wesley Wood Service Experts at 484-401-7577 for support.
  • 168—Wi-Fi radio error. Contact Lyric technical support at 800-633-3991. 170—Internal memory error. Call Lyric technical support at 800-633-3991.
  • 171—Set date and time. Finish these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action necessary.
  • 181/182—Install a new air filter. Clear the display by hitting “dismiss” after installing a fresh filter.
  • 184—Replace humidifier pad. Clear the monitor by hitting “dismiss” after adding a new pad filter.
  • 185—Put in a new dehumidifier filter. Clear the monitor by touching “dismiss” after putting in a fresh filter.
  • 187—Clean or replace ventilator filter. Clear the screen by touching “dismiss” after putting in a fresh filter.
  • 188/189—Install a new UV bulb. Ring Wesley Wood Service Experts at 484-401-7577 for assistance.
  • 210—Register online for outdoor temperature. Get the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and exterior temperature. Download the Lyric app to do this step and ensure proper thermostat operation.
  • 399—No Internet. Check your network settings.
  • 400—No Wi-Fi signal. Wait for the thermostat to reconnect or select new Wi-Fi network.
  • 508—Wi-Fi not configured. Use the Lyric app and follow the steps to configure your thermostat.

For more specifics, look at this thermostat’s user manual.

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump requires service. Contact Wesley Wood Service Experts at 484-401-7577 for support.
  • 168—Wi-Fi radio error. Reach Wesley Wood Service Experts at 484-401-7577 for assistance.
  • 170—Internal memory error. Reach Wesley Wood Service Experts at 484-401-7577 for support.
  • 171—Set date and time. Finalize these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Reach Wesley Wood Service Experts at 484-401-7577 for assistance.
  • 175—AC power resumed. No action necessary.
  • 177—Indoor temperature sensor error. Contact Wesley Wood Service Experts at 484-401-7577 for support.
  • 178—Outdoor temperature sensor error. Reach Wesley Wood Service Experts at 484-401-7577 for help.
  • 181/182—Install a new air filter. Clear the screen by touching “dismiss” after adding a fresh filter.
  • 183—Wash humidifier tank and replace water filter. Clear the thermostat by hitting “dismiss” after doing these procedures.
  • 184—Get a new humidifier pad. Clear the thermostat by tapping “dismiss” after installing pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by hitting “dismiss” after adding a new filter.
  • 186—Rinse ventilator core. Clear the monitor by hitting “dismiss” after doing this task.
  • 187—Clean or replace ventilator filter. Clear the display by touching “dismiss” after buying a new filter.
  • 188/189—Add a new UV bulb. Contact Wesley Wood Service Experts at 484-401-7577 for help.
  • 210—Register online for exterior temperature. Use the Lyric app to do this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get the Lyric app to do this step and ensure proper thermostat operation.
  • 399—No Internet. Check your network settings.
  • 400—No Wi-Fi signal. Wait for the thermostat to reconnect or select new Wi-Fi network.
  • 508—Wi-Fi not configured. Use the Lyric app and follow the procedures to connect your thermostat.

For more details, see this thermostat’s user manual.

Our Experts are Available to Provide Support

If you’re still running into issues after working through the troubleshooting steps, our pros are available to support you. Give us a call at 484-401-7577 and we’ll arrive quickly to figure out the malfunction.

If you use an aging thermostat, today is a fantastic time to think over a new thermostat. Thermostat technology has come a long way lately Ask us for more information on how smart thermostats can make your residence more convenient while helping save on utility costs throughout the year.

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